[giovanni300c]

My 300c has about 1300 miles on it and the first 1000 miles the motor ran very smooth... now the engine runs a little wacky.. the rpm's jump up and down while driving and it seems the car never really knows what gear it wants to go into... is it my driving style or something esle.. its driving me crazy...i know my wife put like 93 octane last gas tank so i thought maybe it was that.. the weather got significantly colder..maybe that...fuel injectors clogged? maybe that...the car actually runs terribly...please let me know of any similar problems before i bring it to the dealer and they tell me nothing's wrong...

 

[First300COwner]

I know how you feel, don't get too worried unless....

Unless you've done some work to your car that might of voided the warranty your biggest concern should be being out of the car for a week. Whatever is wrong with your car it's covered by warranty! Document this problem and keep copies of everything. You might run into a lot more problems within the next 3 year or 36,000 miles and have to file a claim for the lemon law. I had to do that with a new 2001 Honda Prelude, its tranny farted on me 4 times and after that I let the lemon law handle it. Sounds like you might have some tranny issues and maybe some other issue, just take it in because not one person can help you with this problem on this forum, I feel the issues your have are totally mechanical and not electrical and won't be solved by a flick of the switch. The way your describing this problem it sounds urgent and serious, TAKE IT IN!!!

 

[Scarbs]

yep

First is right. Take it in. If you dont like the dealer take it to anyother one. I have had great luck with dealers so far dont be affraid of them.

 

[giovanni300c]

first.. thanx for ur input but i think maybe I over exaggerated on then rpms jumps.. the rpm gauge flutters, i guess is the best way to put it... but its not the gauge because with radio off i can actually hear the engine sound fluttering..its very hard to describe in words... its not the engine going from 4-8 cylinders is it???

 

[midwestrc]

No its not... take it in.

 

[HaTaX]

Does it do it at idle or at crusing speeds? I notice the rough idle when parked but I kind of dig it... Feels like the idle lope of a big V8. =) (I think it's MDS at low RPMS though..)

 

[rmedina]

My 300c has about 1300 miles on it and the first 1000 miles the motor ran very smooth... now the engine runs a little wacky.. the rpm's jump up and down while driving and it seems the car never really knows what gear it wants to go into... is it my driving style or something esle.. its driving me crazy...i know my wife put like 93 octane last gas tank so i thought maybe it was that.. the weather got significantly colder..maybe that...fuel injectors clogged? maybe that...the car actually runs terribly...please let me know of any similar problems before i bring it to the dealer and they tell me nothing's wrong...

I woud have to say it's your gas.. My friend has an 2002 or 03 Mustang and it runs horrible on 93 octane. It was made to run on 87 or 89 octane. I would wait until you fill up with the correct octane.

 

[HaTaX]

Watch your MPG display at a stop light. No doubt it idles all 8.

Watch your MPG in any car at any stop light... Since you're not going anywhere, your MPG will be 0.

Also the lope is more noticable while in park.... Maybe it idles with 4 in park and 8 in drive?

 

[CITADELGRAD87]

I woud have to say it's your gas.. My friend has an 2002 or 03 Mustang and it runs horrible on 93 octane. It was made to run on 87 or 89 octane. I would wait until you fill up with the correct octane.

Wait, are you saying that octane that is too HIGH would adversly affect performance?

I know that it doesn't HELP to run excessivley high octance, but how can high octance pump gas make a car run worse?

 

[HaTaX]

Higher octane is hard to burn for an engine.. The power stored is greater, but it takes more work to get that power out of the fuel... It can be that the engine's calibrations are close to their limits at 91 octane, and the premium fuel he's using is 93... Shouldn't make a big difference, but some motors just don't like high octane fuel...

I know when we get gas for our GT PT we always use Holiday because they carry 93 octane fuel and with a turbo car, you want as high as you can get... Helps avoid pre-ignition. (Pinging)

 

[BUFF_Dragon]

higher octane can cause little hiccups if your vehicle is truely designed for lower, as HaTaX said, its harder for the engine to burn

now if you were to add a CAI, exhaust system, or computer flash... it would probably LOVE that higher octane.. but not run as good on the lower octane....

 

[II kings 9:20]

DC specifically recommends 89 octane for da Hemi, period. Months ago in another theread there was talk of higher octane damaging the engine, urban legend? Who cares? With this MDS, I am not taking any chances, also I am using 5w20 ONLY to reduce the risk of MDS FUBAR (Fouled Up Beyond All Recognition).